This invention relates to the field of chip cards.
A by chip card in the following specification and in the claims refers to a card integrating at least one electronic circuit, for example a microprocessor and/or memory elements, and interface means allowing the card to communicate with a chip card read and/or write device. The interface means can comprise, for example, a zone of electrical contacts on one of the faces of the chip card or a coil allowing a contact-free reading or change of the contents of the card. The majority of current chip cards have standardized dimensions of 53.98.times.85.60.times.0.76 mm. The chip cards are generally manufactured by lamination of a plurality of synthetic layers, the electronic circuit being accommodated in or on one of the internal laminated layers. A microprocessor is any sequential device able to execute a program or a microprogram recorded in a memory internal or external to the microprocessor. A by memory element is any type of read-write memory or read-only memory. A by program is any series of instructions intended to be executed sequentially by a microprocessor or a sequential device. The by the execution of a program refers to the sequence of instructions and the values taken by the variables during a particular running of the program.
Chip cards have an area of application which is becoming broader and broader. Examples include personal identification such as, for example, access cards for reserved or restricted areas, banking cards, payment cards, storage of confidential data, use of automated machines in particular telephone booths, mobile telephones (SIM cards--Subscriber Identification Module--in GSM technology), multiple or seasonal tickets, pay television, etc.
Conventional chip cards require a read-write device adapted to read or modify their contents. Such a device is relatively costly and cumbersome and thus cannot be used everywhere, which limits the possible chip card applications.